bubble up this newterm error

as suggested here: gyscos#778 (comment)

Co-authored-by: Alexandre Bury <[email protected]>

cursive/src/backends/curses/n.rs

@@ -111,7 +111,7 @@ impl Backend {
  let path = CString::new(output_path).unwrap();
  unsafe { libc::fopen(path.as_ptr(), mode.as_ptr()) }
  };
- let _ = ncurses::newterm(None, output, input).unwrap();
+ ncurses::newterm(None, output, input).map_err(|_| io::Error::new(io::ErrorKind::Other, "could not call newterm"))?;
  // unwrap() is guaranteed not* to panic here ^ unless the underlaying
  // ncurses-rs implementation changes API in the future and returns Err
  // for other reasons as well, which we do want to catch/panic due to.